1. Field of the Invention
The present invention relates to a bio-pin which is a peptide-based complex capable of being used for cell transfer, tracing, and treatment, and used in a molecular imaging system and a medical appliance such as a stent.
2. Discussion of Related Art
In recent years, there has been a need for development of bio-materials capable of regulating adhesive strength in the field of applications using stem cells, such as cell transplantation, tissue transplantation, nanotubes, nanowires, microelectromechanical systems (MEMS), nanoparticles, biosensors, biochips, drug delivery, etc. (Nahar et al., 2006, Crit. Rev Ther Drug Carrier Syst, 23, 259-318). However, when endothelial progenitor cells (EPCs) which can be used as transfer cells for treatment of myocardial infarction are transferred to cardiac muscular tissues, most of the transferred cells are washed off at the beginning of cell transfer, and only 3 to 5% of the transferred cells are attached to the target tissues, indicating poor efficiency of the stem cell transfer (Aicher et al., 2003, Circulation, 107, 2134-2139). Since most of the other transfer cells exhibit similar results, there has been various attempts conducted to overcome these problems, but no outstanding methods are found. In particular, there has been research conducted to improve a cell attachment effect by transferring a gene encoding an adhesion protein to cells (Sheyn et al., 2010, Adv Drug Deliv Rev., 62, 683-698). However, since the cells in which the gene is overexpressed may be highly regulated as genetically modified cells in clinical applications in the near future, it is difficult to commercialize technology using these cells.
There is research conducted so far to develop bioadhesives using a bio-friendly material in various fields. Typically, an adhesive extracted from a soybean, a urethane-based foam adhesive commercially available from Naturalock, a starch-based adhesive, a blue mussel (Mytilus Edulis)-derived adhesive, and a sea mussel-derived protein adhesive have been developed for industrial and medical uses (Ciannamea et al., 2010, Bioresour Technol, 101, 818-825; Luhrs and Geurtsen, 2009, Prog Mol Subcell Biol, 47, 359-380; Valenta, 2005, Adv Drug Deliv Rev, 57, 1692-1712; Silverman and Roberto, 2007, Mar Biotechnol, 9, 661-681). However, the bioadhesives are more environmentally friendly than other polymer-based adhesives such as epoxy or phenol resins, but their main aim is based on development of a much powerful type of material for use for surgical sutures or as industrial adhesives. Therefore, it is not suitable to directly apply an adhesive to cells to be transferred for cell treatment and transplantation.
Also, a molecular imaging system, which determines whether the cells to be transferred for cell treatment and transplantation are transferred in vivo or diagnoses diseases, has been used to yield an SPECT-CT image by separating monocytes at a level of an animal model and introducing 111indium oxine into the monocytes (Kircher et al., 2008, Circulation, 117, 388-395), or a study of imaging macrophages using an iodine or gold-nanoparticle contrast agent has been conducted (Hyafil et al., 2007, Nat Med, 13, 636-641). However, such nanoparticles have the serious limitation of diagnosis in that they exude from cells and spread throughout the body.